Apparatus for discharging particle material

ABSTRACT

A device for discharging particulate material from a container with a table to support the particulate material includes a feed unit which is movable on the table for discharging the material through a peripheral outlet opening, and a drive for driving the feed unit; the feed unit includes at least two spaced feeding elements disposed to successively move the material in a direction from the center of the table towards the outlet opening; the feeding elements are arranged, during a full cycle of movement of the feed unit, to be alternately active within an arbitrary section of the table extending between the center part and outlet opening for feeding a layer of particulate material in front of them in the direction toward the outlet opening and inactive while returning to a starting position.

FIELD OF THE INVENTION

The present invention relates to a means for discharging particlematerial from a container, preferably having circular cross section,with a bottom in the form of a fixed table to support the particlematerial in the container, said means comprising a feed unit which ismovable in relation to the table and disposed close to the upper side ofthe table, for discharging the particle material from the containerthrough an outlet means, and drive means for driving the feed unit, saidfeed unit having substantially vertical feeding surfaces facing theoutlet means, said outlet means comprises at least one substantiallyhorizontal outlet opening, extending around at least the main part ofthe table at a distance from its center and which is defined along atleast one side by an edge of the table, said feeding surfaces of thefeed unit extending all around the table, and said feed unit beingarranged to be moved by said drive means during a cycle of movement withaltered directions of feed towards the outlet opening so that during thecycle of movement particle material is fed out to substantially allparts of said outlet opening, and also so that the area of the feedingsurfaces which is active for feeding is substantially constantthroughout the cycle of movement.

BACKGROUND OF THE INVENTION Description of the Prior Art

A number of devices have been suggested for feeding out particlematerial, such as movable arms or blades which rotate or oscillate toand fro and are usually intended for use in combination with one or morescrews. It is also usual to use only a screw arrangement to feed out thematerial. Other examples are feeders with slats or scrapers which bringwith them the material to an outlet opening, the slats or scrapers maymove to and fro or they may be disposed on a continuous belt. A problemencountered with most known feeding devices is that they do not give auniform flow of material down through the container seen in crosssection. Instead the flow may be greater on one side than on the otheror the flow in the middle of the container may differ from that at thewalls. The problem is particularly serious when the material is to betreated with a treating agent in gaseous or liquid form at or withoutincreased temperature since the quality of the material will be unevendue to the fact that it will be treated for varying lengths of time as aresult of varying flow rates seen in a cross section of the container.An example of such an application is in the pulp industry when steamingchips. Before being fed into a digester the chips are treated with steamin a chip bin in order to heat the chips to a desired high temperatureand at the same time to remove air from the interior of the chips. Itwill be understood that with the varying flow rates described in thechip bin, the steamed chips fed out will vary in quality so that thechips will have different temperatures and varying amounts of retainedair.

GB-948 444, NO-129 085 and EP-A1-0 247 682 describe various devices fordischarging particle material. The known devices have one or more of thedrawbacks discussed above. EP-A1-0 247 682 is not useful for chips,either, since it utilizes eccentric rings which feed the material in twoopposite directions towards adjacent outlet openings at both sides ofeach ring. Owing to the oblong thin shape of the chip it is not possibleto repeatedly change its feeding direction when a uniform flow is to beobtained.

SUMMARY OF THE INVENTION

The object of the present invention is to essentially reduce theabove-mentioned problem and provide a means discharging the material insuch a manner that the flow in the container becomes more uniform in across section through the column of material. Bases are thus created forachieving a more uniform quality in the material fed out of thecontainer and which is treated in the container with a suitable fluid,e.g. steam or moist, heated air.

The invention is substantially characterized in that said feed unitcomprises at least two spaced feeding elements disposed to successivelymove the material in direction from the center part of the table towardsthe outlet opening, and that said feeding elements are arranged, duringa full cycle of movement of the feed unit or a part of the cycle ofmovement, to be alternately active within an arbitrary section of thetable extending between the center part and outlet opening for feedinglayer of particle material in front of them in the direction to theoutlet opening, and inactive while returning to a starting position.

One of said feeding elements is thus centrally located and it has arelatively small horizontal extension (corresponding to the diameter inthe case of a circular table) so that also particle material in thecenter of the table can be fed therefrom by the central feeding surfaceto the next feeding element. As indicated the material is fedsuccessively in said direction towards the outlet opening which meansthat the table surface is whole, i.e. without any apertures or gaps,between two adjacent feeding elements. Thus, material which is fed by aninner feeding element will be fed further in the same direction by thenext, feeding element together with further material adjacent thelast-mentioned feeding element. It is understood that each feedingelement has only one feeding surface and that this feeding surface facesto the periphery of the table.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described further in the following with referenceto the accompanying drawings.

FIG. 1 is a side view of a container with a means for feeding outmaterial in accordance with a first embodiment of the invention.

FIG. 2 is a section along the line II--II in FIG. 1.

FIG. 3 is a side view of the lower part of a container provided with ameans according to a second embodiment of the invention.

FIG. 4 is a section along the line IV--IV in FIG. 3.

FIG. 5 is a side view of the lower part of a container provided with ameans according to a third embodiment of the invention.

FIG. 6 is a section along the line VI--VI in FIG. 5.

FIG. 7 is a section through an arrangement with sliding plate forreducing the friction between the feed unit and the table.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the lower part of a vertical cylindrical container whichmay be rigidly mounted onto a floor in a building or onto a stand bymeans of an attachment means 2. Particle material is supplied at the topof the container through supply means (not shown). At the lower end ofthe container is an enlarged housing 3 which is considerably larger indiameter than the container 1--at least within the area of a horizontalreference plane RP. The housing is secured to the container 1 by anumber of brackets 4, and encloses an outlet chamber 5 with a scrapingdevice 6 arranged at the bottom. The scraping device 6 is driven by amotor 7 disposed below the housing. Via a suitable gear 8 the motordrives a vertical shaft 9 which extends through the bottom wall of thehousing and drives the scraping device 6 which is provided with aplurality of scrapers 10. A chute 11 is connected to the housing 3 at aperipheral point of the bottom wall, so that the material carried alongwith the scrapers 10 is conveyed down into the chute 11.

The orifice of the container 1 is located in or immediately above theoutlet chamber 5. The lower end portion of the container is formed by acylindrical ring 12 which is slidably movable on the outside of thecontainer and can be adjusted vertically by means of a plurality ofadjusting means 13. The position of the lower horizontal edge 14 of thecontainer can thus be adjusted in relation to said reference plane RP. Ahorizontal, circular table 15 is also arranged in the outlet chamber 5and secured to said brackets 4. The upper surface 16 of the table 15coincides with said reference plane RP and defines a vertical, circularoutlet gap 21 with the edge 14 of the container. The size of the gap 21is thus regulated with the adjusting means 13. The diameter of the table15 is larger than that of the container 1 measured at its lower edge 14so that a sufficiently large outer part 17 is formed which is locatedradially outside the imagined extension of the container as indicated bya reference circle RC in FIG. 2. The outer part 17 is intended to takeup material with a certain angle of repose. The diameter of the table 15is less than that of the housing 3 measured at said reference plane RP,so that a sufficiently large horizontal gap-shaped outlet opening 18 isformed between the periphery of the table 15 and the inner side of thehousing 3. This outlet gap 18 is thus circumpherential or continuousapart from the interruptions caused by the brackets 4. In the preferredembodiment shown the table is free from outlet gaps since such innergaps would permit material to fall down therethrough from the column ofmaterial located above the table without controlled feeding resulting inan uneven flow.

The housing 3 disposed below the container 1 is provided with a specialdischarging device comprising a feed unit 19 movable in a plane parallelwith the upper surface 16 of the table, a drive means 20 to effectmovement of the feed unit 19, and a plurality of stationary, circularcounter-rings 26, 27. In the embodiment shown the movable feed unit 19consists of a plurality of feeding elements in the form of twoconcentric, circular feeding rings 22, 23, and a circular feeding disc24 disposed at the center C₁ of the feeding rings. The feeding disc 24and the two feeding rings 22, 23 are joined together by connecting armsplaced in the form of a cross. The movable feed unit 19 is disposed.eccentrically above the table in relation to its center C₂. Theeccentric displacement a i.e. the distance between C₁ and C₂, ispredetermined. In the embodiment shown two counter-rings 26, 27 are usedwhich are concentric with the circular table 15 and secured to its uppersurface 16. The inner, fixed counter-ring 27 is surrounded by the inner,movable feeding ring 23, which in turn is surrounded by the outercounter-ring 26. The greatest distance b between the movable feedingring/feeding disc 22, 23, 24 and the nearest stationary counter-ring 26,27, respectively, is slightly greater than twice the distance a so thatfrictional contact is prevented when the distance between the movablefeeding ring/feeding disc 22, 23, 24 and a nearest stationarycounter-ring 26, 27, respectively, assumes its smallest value, whichsmallest distance can be designated c. The following equation thusapplies:

    b=2a+c.

The movable feeding rings 22, 23 have a forward, substantially verticalfeeding surface 28 which thus faces radially outwards towards theperiphery of the table 15 and towards the outlet gap 18, and a rear,inclined slide surface 29 which thus faces towards the center C₂ of thetable, whereas the inner feeding disc 24 is provided with acorresponding, substantially vertical feeding surface 30. The stationarycounter-rings 26, 27 are provided with a forward, substantially verticalcounter surface 31 which thus faces radially outwards towards theperiphery of the table, and a rearwardly inclined slide surface 32 whichthus faces towards the center C₂ of the table. The slide surfaces 29, 32allow material to pass more easily over the various rings upon relativemovement between them and the material. Thus, the slide surfaces 29, 32prevent the material to be moved in an opposite direction with respectto the feeding direction desired.

The driving means for moving the feed unit 19 comprises four pneumaticor hydraulic cylinders 33, pivotably mounted on brackets 34 on theoutside of the housing 3 by means of vertical pins 35. The cylinders aredirected substantially radially with the table 15 and their piston rods36 extend through sealed openings in the wall of the housing 3, into theoutlet chamber 5 beneath the table 15 to a position within the areacovered by the outer feeding ring 22 on the upper surface 16 of thetable. For each cylinder the drive means includes an eccentric drivemember having a vertical shaft 37 rotatably journalled by means of abearing 38 mounted in the table. At the lower end of the shaft 37 is ahorizontal arm 39 for eccentric, pivotable journalling of the piston rod36 by means of a vertical lower pin 40. The upper end of the shaft 37 issecured to a circular plate 41 at its center, the plate 41 beingreceived in a corresponding recess in the table and being rotatablyjournalled in the recess. An upper vertical pin 42 is disposed at theperiphery of the plate 41 for eccentric, pivotable journalling of theouter feeding ring 22 in relation to the plate 41. The upper pin 42 isaxially aligned with the lower pin 40. The rotatable plates 41 aredisplaced 90° in relation to each other around the table 15 and at thesame distance from the center C₂ of the table so that they internallytouch said reference circle RC. The eccentric journalling point, formedby the upper pin 42, of the outer feeding ring 22 on a plate 41 isdisplaced 90° in relation to the journalling point 42 on the followingor preceding plate 41 seen in the circumference of the table and seen inrelation to the radius of the table 15 which intersects the center ofeach plate 41. Switching in of the cylinders 33 is governed by a controldevice with position transducers so that the cylinders 33 are connectedin alternately or intermittently in accordance with a specific sequenceto withdraw each piston rod 36 when the eccenter pin 42 on the rotatingplate 41 moves towards the outlet gap 18. With the aid of the cylinders33, which are suitably single-acting cylinders, all four plates 41 willrotate continuously and, thanks to the eccentrically placed pins 42 withmutually different positions on the plates 41, the outer feeding ring 22will move a corresponding eccentric circular movement in relation to thecenter C₂ of the table. The radius of the eccentric circular movementthus corresponds to the distance between the center of the plate 41 andthe upper pin 42 and also said distance a. The feed unit is thusprevented from rotating about its own center C₁ since the eccentricdrive members are peripherally connected to the feed unit. When eacharbitrary point P₁ on the feeding surface 28 of the outer feeding ring22 is nearest said reference circle RC and opposite an imagined fixedpoint P₂ thereon, this point P₁ will describe a circle during theeccentric circular movement of the outer feeding ring 22 correspondingto the circle described by the eccentrically placed pin 42 on each plate41. In other words, the process can be described as epicyclic since theouter feeding ring 22 will move around inside the reference circle RC.Since the inner feeding ring 23 and the central feeding disc 24 arepermanently connected to the outer feeding ring 22, they will move in acorresponding manner. In other words, without rotating about its owncenter C₁, the feed unit 19 will move with its center C₁ in a circle,the center of which coincides with the center C₂ of the table and whichhas a radius a. Two more rotatably journalled plates 43 are provided inrecesses in the table in conjunction with the inner feeding ring 23which, with the aid of pins 44 is eccentrically pivotably connected tothe plates 43. A plurality of sliding plates 45 are also secured atseveral places on the table 15 to support the feed unit 19 and reducethe friction during its circular movement.

The shown container with its discharging device constitutes a chip binfor steaming chips. For this purpose the housing 3 is provided with aplurality of connections 46 for the supply of steam or pre-heated moistair which penetrates up through the chip bed in the bin 1.

FIGS. 3 and 4 show another embodiment of a discharging device accordingto the invention. The main difference from the embodiment shown in FIGS.1 and 2 is that the means comprises a single eccentric drive means andthat this is disposed below the table 15 in its central portion. Thetable 15 consists of an outer, larger, stationary part 50 and acentrally located part 51 which closes an assembly housing 52 and isrotatable. The central table part 51 is supported; by a sleeve 53secured to a rotatable shaft 54, the center line of which coincides withthe center C₂ of the table. The shaft 54 is journalled in a bearing 55which is secured by brackets 56 to the assembly housing 52, the lattersupporting the entire eccentric drive means. The rotatable sleeve 53carries a bearing sleeve 57 for a vertical, upper, eccentric pin 58placed eccentrically in relation to the center C₂ of the table andjoined to the feeding disc 24 of the feed unit 19. This connection mayadvantageously be pivotable so that the feed unit can be allowed topivot about its bearing shaft at the pin 58 while at the same timeperforming the eccentric circular movement. The four piston rods 33 areflexibly connected by vertical pins 62 to a horizontal connecting piece59, a vertical lower pin 60 being journalled in the connecting piece 59and in a horizontal connecting arm 61 permanently connected to the lowerend of the central shaft 54. The upper and lower eccentrically placedpins 58, 60 are axially aligned with each other. The hydraulic cylinders33 are activated in the same manner as described above, in a controlledsequence one after the other so that the lower eccentric pin is moved ina circle and turns about the shaft 54, the rotation of which causes theupper pin 58 to move in a corresponding circular path around the centerC₂ of the table, whereby the central part 51 of the table is alsorotated and the feed unit 19 is moved in an eccentric circular movementas described above. The table 15 may be provided with sliding plates forthe feed unit 19 as described previously.

FIGS. 5 and 6 show another embodiment of a discharging device accordingto the invention. The main difference from the embodiment shown in FIGS.1 and 2 is that the hydraulic cylinders 33 are arranged above the table15 so that the pistons 36 can be flexibly connected to the feed unit 19without any intermediate eccentric drive means which would have to passvertically through the table. The flexible connections between pistonrods 36 and feed unit 19 are provided by vertical pivot pins 65 whichcan advantageously be arranged within the area of the outer part 17 ofthe table to avoid being influenced by the pressure from the column ofmaterial in the container. For this purpose the feed unit 19 is providedwith radial pivot arms 66 for flexible connection with the piston rods36 via said pivot pins 65. The pivot arms 66 are suitably arranged inthe extension of, or constitute extensions of the connecting arms 25mounted in a cross. The eccentric circular movement of the feed unit 19is provided by selecting different relative positions for the pivot pins65 in relation to the center C₂ of the table, for instance. The pivotpins 65 describe the same circular movement as the pins 42 in the firstembodiment and are therefore at different points along such a circle,with the same 90° displacement as shown in FIG. 2. It will be understoodthat the piston rods 36 protrude different distances from theirhydraulic cylinders 33 and in different directions in relation to thetable 15. The hydraulic cylinders 33 are connected intermittently inorder to alternately pull the feed unit 19 towards them so that the unitand its outer feeding ring 22 follows the reference circle RC which isconcentric with the table. The feed unit 19 will thus execute aneccentric circular movement with respect to the center C₂ of the table,in the same way as in the embodiments described above, in order tocontinuously feed material from the center C₂ of the table 15 outtowards the outlet gap 18. In all the embodiments shown, therefore theflow of material which is fed out from the table and falls down throughthe outlet gap 18 will move continuously around the outlet gap 18 andwill always be .located opposite the area of the outer feeding ring 22located nearest and approaching said reference circle RC. Instead ofsliding plates like those used in the embodiment according to FIG. 2, aplurality of radial sliding rods 67 are rigidly mounted on the uppersurface of the table to support the feed unit and reduce frictionagainst the table.

FIG. 7 shows a suitable embodiment of a device for reducing the frictionbetween the feed unit 19 and the table 15, which device can be mountedat several points on the table. An assembly ring 70 is welded to thelower side of the table to surround a circular opening 71 in the table.A bottom ring 72 is screwed to the assembly ring 70 and carries asupport plate 73 which is welded to the bottom ring 72 and is providedwith a central aperture 74. A sliding plate 75 is located in the opening71 in the table 15, this plate resting on the support plate 73 andhaving a central pin 76 which is received in the central aperture 74 ofthe support plate 73. The aperture 74 is closed from below by a lid 77and a seal 78 is placed inside the lid 77 to seal between the supportplate 73 and the central pin 76 of the sliding plate. The opposingsurfaces of the sliding plate 75 and support plate 73 form slidingbearing surfaces 79 which are provided with grease from a centrallubricant aggregate via a channel 80. Excess grease penetrates out to anannular space 81 located radially outside the support plate and slidingplate. A plurality of small holes 82 in the support ring communicatewith the space 81, which allow grease to be pressed out thus indicatingthat the space 81 is entirely filled with grease. A recess is providedin the connecting arm 25 located above the sliding plate 75, this recesscontaining an assembly ring 83 welded to the connecting arm 25 and abushing 84 inside the ring, the bushing in turn surrounding acylindrical sliding roller or plate 85. The sliding roller is arrangedeccentrically in relation to the sliding plate 75. The sliding roller 85is enclosed by a lid 86 welded to the assembly ring 83 and rests on theupper surface of the sliding plate 75. During normal operation it isprevented from rotating about its vertical central axis by the frictionengagement occurring between the two cooperating surfaces caused bypressure from the material in the container 1. The opposing surfaces ofthe sliding roller 85 and lid 86 and the bushing 84 form sliding bearingsurfaces 87 and are provided with grease from said central lubricantaggregate via a channel 88. The excess grease penetrates out to theoutwardly open space 89 between the connecting arm 25 and the table 15and prevents impurities from penetration to the sliding bearing surfaces87. Excess grease also penetrates to this space 89 from the space 81outside the sliding plate 75 via an annular gap 90 and preventsimpurities from penetrating down to the sliding bearing surfaces 79 onthe lower side of the sliding plate 75. During operation the slidingplate 75 and sliding roller 85 rotate and the load from the feed unit 19is taken up by the lubricated sliding bearing surfaces 79, 87. Duringnormal operation these sliding bearing surfaces are lubricated withgrease and well protected from impurities, thus giving minimum wear onthe components. Should a malfunction prevent the feed unit 19 fromperforming its eccentric circular movement, the friction engagement willbe released and the sliding roller 85 will slide on the sliding plate75. Operation will therefore not be interrupted. The sliding roller 85may alternatively be journalled in the feeding rings 22, 23 of the feedunits previously described.

Since the feed unit 19 has several feeding elements 22, 23, 24 locatedradially outside each other, and since these are continuous, the feedingsurfaces 28, 30 increase proportionally to the distance from the centerof the table. The embodiments described enable material to be fed fromall points of the bottom area of the column of material during a cycleof movement of the feed unit 19. Furthermore, the area of the feedingsurfaces which are active and in movement for feeding is constant duringeach phase (Δt) of the cycle of movement irrespective of the directionof the feeding surfaces 28, 30. By cycle of movement (or part thereof)is meant the time required for a certain point on the feeding surfacesto perform a full feeding movement from a starting position to theoutlet gap 18 and then return to the starting position until the momenta new feeding movement is begun.

Motors can be used to operate the feed unit, instead of pneumatic orhydraulic cylinders. In the embodiment illustrated in FIGS. 3 and 4 theshaft of a motor may thus be connected to the shaft 54, either directlyor via a suitable gear. In the other embodiments the cylinders may bereplaced by motors, each driving a crank arm or the like correspondingto the piston rod 36.

The invention is not limited to the embodiments shown with a circulartable and a feed unit which is turned around the center of the table,but is also applicable for square or rectangular tables, for instance,where the feeding elements are frame-like in shape and are moved infirst and second or several to and fro movements in which the movementsform angles of 90° with each other. Furthermore, the outlet gap 18 maybe defined by two spaced edges of the table, i.e. the outlet gap islocated between the periphery and the center of the table, the tablebeing circular or rectangular in shape, preferably square.

With the expression "fixed table" is meant that the table has at least amain part which is stationary and that it can include a rotatable innerpart as shown by one of the embodiments described above.

We claim:
 1. An apparatus for feeding particulate material from acontainer of the type having a bottom having an opening, said apparatuscomprising a table for location beneath the bottom of the container toreceive the material under gravity flow onto said table from theopening, said table having an outer peripheral edge and a center, afeeding unit disposed on said table for movement toward and away from atleast a portion of said outer peripheral edge, said feeding unitincluding at least one slide member carried on said table and having afirst surface facing generally outwardly in a direction of movementtoward said outer peripheral edge and a second surface facing generallyinwardly in a direction of movement away from said outer peripheraledge, said first surface being shaped to engage and move material towardsaid outer peripheral edge to discharge material from the table and saidsecond surface being shaped to minimize movement of material towards thecenter as said at least one slide member is moved generally away fromsaid outer peripheral edge.
 2. The apparatus as claimed in claim 1,wherein said apparatus includes drive means for moving said feeding unitcontinuously in altered directions of feed in relation to said outerperipheral edge and intermittently in altered directions of feed inrelation to said outer peripheral edge.
 3. The apparatus as claimed inclaim 1, wherein said second surface of said at least one slide memberis inclined relative to said table, said inclined surface slopingtowards said center of said table.
 4. The apparatus as claimed in claim1, wherein said table is disposed at a selected vertical distance belowsaid opening of the container to form a vertical peripheral gaptherebetween, said container being of the type having a cross-sectionalarea less than the area of said table, said bottom of said containerforming a housing being provided to surround said table with said tablebeing imperforate between said outer peripheral edge and said centerthereof.
 5. The apparatus as claimed in claim 4, wherein said table iscircular and said at least one sliding member further comprises aplurality of concentric feeding elements each having a said firstsurface and a said second surface, said-feeding elements being disposedat predetermined distances from each other, said at least one slidemember further including connecting arms connecting said feedingelements for movement, said apparatus including drive means connected tosaid connecting arms for moving said connecting arms in an eccentriccircular movement about the center of said table whereby an arbitrarypoint on said feeding elements moves in a corresponding circle with aradius corresponding to a predetermined distance to urge materialtowards said outer peripheral edge.
 6. The apparatus as claimed in claim5, wherein said feeding unit further includes a centrally placed feedingdisk disposed concentric with respect to said feeding elements forfeeding material from the center of said table.
 7. The apparatus asclaimed in claim 6, wherein a counter ring is secured to said tableconcentrically with the center of said table and located radiallyinteriorly of each said feeding element, said counter ring having asubstantially vertical counter-surface facing in the direction of saidfirst surfaces of said feeding elements to prevent material from movingtowards said center of said table whenever a portion of one of saidfeeding elements moves towards said counter-surface, said counter ringbeing provided with an inclined slide surface facing the center of saidtable.
 8. The apparatus as claimed in claim 7, wherein said drive meanscomprises at least two power cylinders disposed horizontally below saidtable.
 9. The apparatus as claimed in claim 8, wherein each powercylinder has a piston rod extending below said table and connected tosaid feeding unit by at least one eccentric drive member, said at leastone eccentric drive member being disposed adjacent to said center ofsaid table.
 10. The apparatus as claimed in claim 9, wherein said atleast one eccentric drive member has an upper vertical pin on which saidfeeding unit is rotatably journaled.
 11. The apparatus as claimed inclaim 7, wherein said drive means includes at least two power cylindersdisposed horizontally in said housing, each said power cylinderincluding a piston rod extending vertically above said table, eachpiston rod being connected to a vertical pivot pin, so that, when eachpiston is activated in sequence, intermittently, said respective powercylinder will sequentially move said feeding unit in said eccentriccircular movement.
 12. The apparatus as claimed in claim 1, whereinfriction-reducing means are disposed between said feeding unit and saidtable, said friction-reducing means comprising circular sliding platesmounted on said table.
 13. The apparatus as claimed in claim 12, whereinsaid sliding plates being rotatable on load-absorbing sliding bearingsurfaces.
 14. The apparatus as claimed in claim 13, wherein each slidingplate includes a sliding roller pivotally journaled and enclosed with abushing in an enclosure with said bushing surrounding said slidingroller, said enclosure forming one of the load-absorbing sliding bearingsurfaces, said sliding plate cooperating with a support plate located onsaid sliding plate to form another of the load-absorbing sliding bearingsurfaces, a supply for lubricant, gaps being provided between saidsliding plate and, said table to allow flow of lubricant from saidlubricant supply onto said sliding bearing surfaces, said sliding rollerand sliding plate having opposing surfaces in releasable frictionalengagement with each other.
 15. The apparatus as claimed in claim 14,wherein said container and a housing beneath said table are providedwith ducts for a supply of fluid for treating the particulate material.16. The apparatus as claimed in claim 15, wherein said containerconstitutes a chip bin and means are provided for connecting said ductswith said supply of fluid of one of steam, or moist, heated air forsteaming the chips.